4.2 Complete each sentence by choosing from the following devices: touch screen, trackball, touchpad, webcam.

Решение:

• 1. A trackball is a stationary device that works like a mouse turned upside down. You roll the ball with your hand to move the pointer on the screen.
• 2. Touch screen, touchpad are used in museums, information centres and Internet kiosks. You use your finger to point directly to objects on the screen.
• 3. A webcam is used to send live video images via the Internet.
• 4. A touchpad is found on notebook PCs. You use it by pressing the sensitive pad with a finger.